Size- and dose-dependent reduction of oxidative stress in l929 fibroblasts by silicon nitride particles

IntroductionParticle-induced oxidative stress in cells is a unifying factor that determines toxicity and carcinogenicity potential in biomaterials. A previous study by Bladen et al. showed the production of significant levels of reactive oxygen species (ROS) following the stimulation of phagocytes by UHMWPE and CoCr wear debris [1]. Latest generation bearing materials such as silicon nitride also need to be tested for potential generation of ROS in phagocytic cells. This study aimed to investigate the production of reactive oxygen species in L929 fibroblasts stimulated with clinically relevant doses of nanoscale and micron-sized silicon nitride (Si3N4) particles, silica nanoparticles, and CoCr wear debris. Silica nanoparticles were included as a comparison material for situations where the Si3N4 particle's surface are oxidised to silicon dioxide [2].Materials and MethodsSi3N4 particles (<50 nm and <1 µm, Sigma), silica nanopowder (<100 nm, Sigma) and clinically relevant CoCr wear particles were heat-treat...